FAQ’s about Bioaugmentation of Wastewater Frequently asked questions about the bioaugmentation of wastewater. Q. What is bioaugmentation? A. Bioaugmentation is simply the addition of specifically selected microorganisms (mainly bacteria) to wastewater. When properly implemented bioaugmentation of wastewater will improve the performance of the plant. Q. I’ve heard about using “bugs” and bioremediation but isn’t that just snake oil? A. In the past, there were a lot of snake oil salesman peddling magic bacteria that could do wonderful things at treatment plant. Bioaugmentation companies had a reputation worse than that of a sleezy lawyer. The myth continue because treatment plant operators normally have a background in engineering, not biology. The wastewater engineers found very little math to evaluate wastewater treatment bacteria. So instead of bioaugmentation, most industrial and municipal wastewater treatment plants used polymers and chemicals to treat their wastewater problems. Q. So what can bacteria and bioaugmentation really do? A. First, its important to remember that bacteria are alive. They have certain nutrient requirement that they need to live, grow, and reproduce. Here’s a quick list of the most important parameters: Dissolved Oxygen – Greater than .5mg/L Temperature – 50-95 degrees F. pH 6-9 Ammonia 1-3 mg/L Phosphate .5-2 mg/L Yes, a wastewater treatment plant can operate out side...

The Role of Bacteria in the Industrial Wastewater Treatment Process Part 2 Here’s the next part of our series on bacteria in the industrial wastewater treatment process. The typical growth rate curve of a bacterial culture, known as the bacterial growth rate curve, is a result of the four following phases of bacterial growth: The Bacterial Growth Cycle Lag Phase (Sometimes called initial phase). When bacteria are first introduced into an environment, little growth will take place until they adapt to their new environment. In fact, it generally takes several generation times before the bacterial numbers begin to significantly increase. In practice, the lag phase typically lasts three hours or longer. Log Phase (Logarithmic Phase). Once full growth and cell reproduction is underway, the bacterial growth curve develops the log phase. This is the phase where the bacteria are rapidly dividing. This phase is limited by the food source and waste buildup. Stationary Phase. This phase occurs when some bacteria are growing and reproducing while others are dying. The actual number of living, viable organisms will remain fairly constant. Death Phase (Sometimes called log death phase). After a period of time, the environment becomes loaded with bacterial waste products, food supply is depleted, and the entire system begins to...

The Role of Bacteria in the Industrial Wastewater Treatment Process In general, an area that is largely misunderstood in industrial wastewater treatment is the role played by bacteria, both indigenous and applied via bioaugmentation. With few exceptions, most industrial wastewater treatment of organic compounds is intended to take advantage of the natural processes of wastewater treatment bacteria. Bacteria may be aerobic, anaerobic or facultative anaerobes. Aerobic bacteria require oxygen to perform their metabolic functions and reproduce. Anaerobes cannot live and reproduce in the presence of oxygen. Facultative bacteria have the ability to live either in the presence or absence of oxygen. For the purposes of our discussion, we’ll talk about aerobic bacteria and discouraging or controlling the anaerobes. In the typical industrial wastewater treatment facility, air is added to improve the metabolism and functioning of the aerobic bacteria. This addition of air is also done to enhance the aerobes at the expense of the anaerobes. A number of factors are controlled at an industrial wastewater treatment plant. All of them with the idea of improving the environmental conditions for the native bacteria. Conditions that are sometimes controlled are: Settling pH Temperature Agitation Aeration Introduction to Bacteria Bacteria may be classified in a number of ways like size, shape, genus,...

Hydrogen Sulfide (H2S) and Bacteria It is well known that wastewater and sewage has a very high potential to produce nasty odors such as hydrogen sulfide (H2S, ammonia, indoles, skatoles and mercaptans. Of these hydrogen sulfide (H2S) is arguably the most import mainly due to toxicity, its ability to corrode materials, and it is the major source of odor problems at wastewater treatment facilities, manholes, and lift stations. The conditions leading to hydrogen sulfide formation favor the production of other odiferous organic compounds. So solving an H2S odor problem can often solve other wastewater odor problems as well. Sources of Hydrogen Sulfide in Wastewater Sulfur is present in both human and livestock solid wastes and sulfates are found in most water supplies. Almost all wastewater has a sufficient amount of sulfur for both anaerobic bacteria and facultative bacteria to produce hydrogen sulfide. Generally, these bacteria produce H2S as a byproduct of their metabolism. By a process called anaerobic respiration, anaerobic bacteria oxidize organic compounds while reducing sulfate (SO4) to hydrogen sulfide (H2S). Interestingly, sulfate reducing bacteria are considered one of the oldest forms of life on earth. They are some 3.5 billion years old. Hydrogen Sulfide Production Rate The rate that anaerobic bacteria produce...

Why Aeration Alone Won’t Make My Lagoon Odor Go Way? Here’s the situation. You have just purchased, or recommended, the company purchase, an expensive aeration system to take care of your lagoon odor problems. After all, the salesman said it would work. He explained that aerobic bacteria don’t create those nasty H2S odors, anaerobic bacteria do. So by simply adding aeration, you’ll change the environment in the lagoon. And Presto – Rotten Egg Odor Gone. No more neighbors complaining about lagoon odor. So you spend the money, install the aeration system and turn it on. Unfortunately, the odor problem doesn’t go away. IT GETS WORSE! An Overwhelming stench of hydrogen sulfide fills the air and your nostrils. The installer says not to worry, it will get better over time. So what just happened? Why didn’t the lagoon odor go away with aeration? First, we’ll need to talk about the microenvironmental situation in the lagoon. In a typical wastewater lagoon, the wastewater stratifies. In other words, some of the water floats and some sinks. Because of this, only the top layer of the wastewater lagoon receives oxygen. As a consequence, obligate anaerobes ( bacteria that cannot survive in the presence of oxygen) proliferate in the lagoon. Obligate anaerobes (bacteria that...